


Birthday Present

by chasingriver



Series: Slut!lock - Adventures in Holmescest [2]
Category: Sherlock (TV)
Genre: Anal Play, Anal Plug, Blow Jobs, Dom/sub Play, F/M, M/M, Sibling Incest
Language: English
Status: Completed
Published: 2012-04-18
Updated: 2012-07-25
Packaged: 2017-11-03 21:38:42
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 4
Words: 7,318
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/386240
Author URL: https://archiveofourown.org/users/chasingriver/pseuds/chasingriver
Summary: <blockquote class="userstuff">
              <p>Sherlock receives a birthday present from Mycroft. </p>
<p>The story is set sometime after Quiet Desperation.</p>
            </blockquote>





	1. Birthday Summons

**Author's Note:**

  * Inspired by [Holmescest art](https://archiveofourown.org/external_works/7997) by Unknown (please let me know if you know who did this!). 



> Warning: sibling incest
> 
> There is NSFW art by the amazingly talented [sexlock](http://sexlock.tumblr.com) at the end of the story! Many thanks to the lovely [Deklava](http://archiveofourown.org/users/deklava/pseuds/deklava) for commissioning this, and for doing the beta!

**Summary for the Chapter:**

> Mycroft summons Sherlock to his office to receive his birthday present.

**Notes for the Chapter:**

> Warning: sibling incest

The chime sounded on his mobile. He glanced down at the text as he listened to Lestrade explain why the murderer couldn't possibly have been the second wife.

_Happy Birthday, brother-mine. Come to my office._

Sherlock's body tensed.

"I assure you, Lestrade. It was the second wife. She walked in on her husband with the lady from the corner shop and couldn't bear the thought of being the second ex-wife. Question her. I have to leave."

Lestrade raised an eyebrow quizzically, which Sherlock ignored. He was already out the door and hailing a taxi. Experience had taught him not to delay when he received a summons from Mycroft.

* * *

Anthea looked at him and smiled sweetly. "Happy birthday, Sherlock." There was a faint edge of filthiness to her voice.

She grabbed her Blackberry and left the outer office. He heard her lock the door behind her as she left. She always did.

Mycroft appeared in the doorway to his office. "Hello, brother. Couldn't wait to get here, could you? So predictable." He smiled. "Do come in."

He ushered Sherlock into the plush inner office. "Did I interrupt anything, Sherlock?"

Sherlock squirmed, knowing the idiotic protocols must be played out and obeyed. "Yes, I was on a case."

"Oh, I'm so sorry I interrupted you." The sarcasm in Mycroft's voice made it abundantly clear he wasn't sorry in the least. "Did you tell the lovely Detective Inspector where you were going in such a hurry?"

"No."

"Oh, I really think you should. In fact, the next time I summon you, I'll phone him to make sure you did. What will you tell him, exactly?"

The blood rushed to Sherlock's groin and his heart started beating in his chest. Just the thought of telling anyone else, or even admitting it out loud, made his cock furiously hard.

"That…" He couldn't finish the sentence.

Mycroft fixed an icy stare on him.

"That I need to leave because I have to go and suck my brother's cock." The words tumbled out in a rush. What little blood wasn't in his groin went to his face and coloured his cheeks.

"And why is that?" Mycroft looked at him with a hint of fondness behind his steely blue eyes.

"Because I'm a filthy little cock slut who can't get enough of you."

"Mmm. Quite so, dear brother. Kneel."

Sherlock knelt eagerly on the plush carpet and looked up at his brother with undisguised longing.

"As you're quite aware, it is your birthday. I thought I might give you a little treat."

Sherlock kept silent but allowed himself to hope. Mycroft never let him gratify himself, not at the office.

"Open your shirt."

Sherlock slowly opened the buttons of his dark shirt, his hands shaking. His thin white vest did little to hide his hard nipples.

Mycroft wet his lips. "Odd. It doesn't seem that cold in here. Push up your vest and play with your nipples. I know you like that. You always moan so prettily when I do it."

Sherlock pushed up his vest, the touch of his own hand on his skin making him shiver. He roughly pinched his right nipple. The intense stimulation sent a shock through his body as he threw his head back and drew in a sharp breath. He let it out with a shuddering groan.

"Again."

The other nipple this time – his body trembling and his cock positively aching with need. "Please."

"Please, what?"

"Please, Mycroft. Let me suck your cock."

Apparently satisfied with the answer, Mycroft started undoing the trousers of his dark suit and pushed his pants down just far enough to give Sherlock access to his throbbing erection.

Sherlock leant in, desperate to feel the warm, pulsating head of it in his mouth, but Mycroft pulled back.

"I want to see you pleasure yourself while I fuck your mouth. Just make sure I come first, or I'll make you pay when we get home tonight."

Sherlock considered disobeying – Mycroft's punishments were worth it – but the rare pleasure of being allowed release in his brother's office… that made it worth following the rules. Perhaps if he was good, it wouldn't be a one-time thing.

He hurriedly undid his trousers, aware of the growing wet patch on the front of them. Mycroft smiled in approval at the bare skin and erect penis beneath them. "No pants. Very good, little brother. I see you've been following orders."

Mycroft grabbed Sherlock's hair and forced him roughly onto his cock. Sherlock groaned around it, savouring the musky taste of sex and Mycroft. It went to his head and made him dizzy. He eagerly started sucking and rolling his tongue around it, his fellatio an act of worship. He touched himself almost gingerly – he was already so aroused he didn't want to come before Mycroft did. The feel of his fingers around his cock nearly sent him over the edge, and his cock steadily leaked pre-ejaculate onto the plush carpeting. His other hand squeezed and played with his nipples as he concentrated on Mycroft's cock. He occasionally gave himself a long, torturous stroke as he sucked – any more than that and it would be over all too soon. It only got worse when Mycroft opened his mouth.

"You love this, don't you, little brother? You're such a little cock slut. _My_ little cock slut. Just a word and you come running over here to get on your knees."

Sherlock murmured his assent as best as he could with Mycroft's cock in his mouth. Mycroft's hands in his hair gave him no control over the depth of Mycroft's thrusts, which were getting deeper and more aggressive by the second. He tried desperately not to gag, knowing Mycroft expected better of him. He allowed himself another long pull on his aching cock. He flinched as Mycroft grabbed his hair tighter and fucked his face, hard. His brother was close, he could feel it.

Mycroft saw the surprise on Sherlock's face as he pulled his mouth off his cock, just as he came explosively, all over Sherlock's face and hair. Mycroft's eyes fluttered closed for a second, his body still trembling from the aftershocks. "Clean me, then you may finish yourself off."

Sherlock lapped his brother's cock clean, then licked his own lips to taste the semen on his face. It even clung to one of his eyelashes, obscuring his vision, but he didn't care. All his attention was on his cock as he stroked himself violently to completion. He came with a loud groan all over his own hand, and fell back onto his heels in contented exhaustion. He was still kneeling there, head back, breathing hard and eyes closed, when he felt Mycroft take his hand. His head whipped up in surprise. Mycroft was kneeling in front to him, fully dressed and smiling, licking all the semen from his hand.

"Happy birthday, little brother."


	2. Foreign Minister

**Summary for the Chapter:**

> Sherlock wants more for his birthday, and gets more than he bargained for.

**Notes for the Chapter:**

> Thanks to Deklava for the beta!
> 
>  **Warning:** sibling incest

Mycroft got to his feet and licked the remnants of Sherlock's semen off his hand like a cat delicately washing its paw.

"Please, My. Just let me stay here for the afternoon. I'm sure you'll need another break from your paperwork." He was still on his knees, half dressed and debauched, and now he was begging.

Mycroft rolled his eyes. "London is a vast metropolis, little brother. Surely, you can find _something_ to occupy you for the afternoon. I'll be home at a reasonable hour. After all, it's your birthday, and there will be cake. You know I won't miss that." He gave Sherlock a tight smile, knowing he'd deprived him of his usual sarcastic remark. "Besides, I have a meeting."

Sherlock wiped his brother's ejaculate from his cheek and eyelashes, and pouted. _It's my birthday._

Mycroft grabbed Sherlock's dark curls and pulled him roughly to his feet. "Greedy, aren't you – who said you get all your presents at once?"

Sherlock couldn't keep the smile from his face. _You know you want this too, My._

Mycroft looked at him with amusement. "Strip. Clothes in the bathroom." _Be careful what you wish for, brother-mine._

Sherlock quickly removed his clothes – practically ruined during the afternoon's tryst – and folded them as best he could. He hurried into the plush en-suite toilet and placed them in a pile on the slate floor. He tried not to look too desperate as he rushed back into Mycroft's office. It was difficult, considering he was starting to get hard again.

"Kneel."

He dropped to his knees and was surprised to see Mycroft unlocking a small drawer in his desk. _What are you doing?_

Mycroft just smiled at him and removed a large anal plug. "Open your mouth."

"That'll never fit."

"It's all the lube you're getting, little brother. I suggest you rethink that."

Before Sherlock could say anything, Mycroft forced the large toy into his mouth. His other hand rested firmly on the back of his brother's head so he couldn't squirm away.

Sherlock felt it suck into his mouth with a pop and his lips closed around the narrower part of the base. The back of the toy nudged at his throat, and he struggled to control his gag reflex. Worse, the toy was large enough that it pressed on the roof of his mouth. It felt like he was going to choke, and he tensed in panic. He breathed harder and more quickly through his nose in an attempt to get more air.

_Calm down little brother, you'll be fine. You've had bigger things than that in there._

Mycroft's thoughts sliced through his agitation and he relaxed a little.

_And I believe I was correct; it does fit. Hands behind your back. I'm not going to cuff you, but you know better than to disobey, don't you?_

Holding Sherlock's hair firmly, Mycroft pulled the toy from his mouth and lowered Sherlock's forehead to the floor. As soon as it was out of his mouth, Sherlock sucked in a glorious lungful of air. Mycroft nudged his knees apart with his foot and spread his cheeks so he had a good view of Sherlock's entrance. "Look at you, Sherlock. Can't even wait until we get home to have your arse filled, can you? Such a little whore." Despite Mycroft's language, his tone was affectionate and tender. He placed the spit-slick toy against Sherlock's hole and slowly pushed it inside him.

Sherlock let out a small moan and wriggled his arse against it, begging for more. He let out a whimper as the largest part of the toy slid inside him and his sphincter clamped around the narrow base. It was huge, and it felt like he was stuffed full as he knelt there with his arse in the air.

Mycroft admired his brother's lean form and cupped his hand over one round arse cheek. _Gorgeous. And mine._

_Yes, My. Yours. Always yours._

Mycroft helped him to his feet and gave him a long, slow kiss. He could feel Sherlock's mind going slack.

"Unfortunately, little brother, I have a meeting, and having my naked, aroused younger brother in the room would probably cause a bit of an international incident."

Sherlock headed toward the bathroom.

"No." Mycroft smiled, and Sherlock stopped in his tracks. "Under the desk."

Sherlock raised his eyebrows and smiled.

The desk was a huge, wooden thing that would have overwhelmed any normal office. The area underneath it was surprisingly roomy. Sherlock-sized, even. Especially if Sherlock didn't mind resting his head in his brother's crotch.

_I have a feeling this will be a rather memorable meeting, Sherlock._

Sherlock's entire body tingled in anticipation. Mycroft had never let him do this. He got on his hands and knees and shuffled awkwardly under the desk, grateful that his wrists were unbound. The huge plug in his arse didn't hinder his movement, it just made him incredible _aware_ of it – of any movement he made.

Once he'd settled himself underneath the desk, Mycroft sat in his chair and dipped his head down to see him.

"Made yourself comfortable I see?"

"Not really, no."

"Good," he smiled. "Now, this meeting shouldn't last too long, but it does promise to be incredibly dull; your job is to make it interesting. Make sure I look nothing short of impeccable after you're done with me. I don't want to stand up and wish the Foreign Minister 'Good day' with my trousers half-zipped. And before you get any ideas about something like that being amusing, be assured that I'll just withhold any sort of pleasure for longer than you care to think about. Understand?"

"Yes, My."

"Make me come at least once; I do love conducting negotiations through an orgasm while keeping a straight face."

"Gladly."

_Good. Silence from now on. And I'd better not hear you sucking my cock; if I can hear you, so can he._

_Ready and waiting, brother-mine. Fuck, wait!_

_What?_

_What about the smell of semen?_

_Well, you'll just have to be really diligent about not spilling any, won't you?_

Mycroft stood and Sherlock heard him leave the inner office. He returned, a few minutes later, with a second set of footsteps.

"Please, have a seat, Minister."

Sherlock heard the cushions of the guest chair exhale a little as the Foreign Minister sat. Mycroft sat a few seconds later, and they began an incredibly dull discussion about the monetary crisis.

Sherlock almost immediately tuned it out. There was work to be done. He braced himself against the sides of the desk with his feet; he'd need both hands free in order to do this silently. He grinned as he ran both hands along the insides of Mycroft's thighs.

Mycroft didn't flinch. _That's your opening move, Sherlock? Honestly…_

Sherlock knitted his brows and didn't grace Mycroft with a reply. Nimble fingers made quick work of his belt and his trouser buttons. He lowered the zip at a glacial pace, irritated to find his brother still soft.

_Really, Mycroft? The thought of me naked underneath your desk does nothing for you?_

_I wouldn't say that, but you are competing with a refractory period longer than your own and some mind-numbing foreign economics. I suggest you work harder._

Pants: silk boxers. Mycroft wouldn't be able to shift in his chair to slide them down. Perhaps he could tuck the front of them underneath his balls? The only other option was the slit in the front. Where was the challenge in that? He very delicately grasped the waistband and lowered them as far as he could, lifting his brother's soft cock and balls and placing the waistband underneath them. It was a tight fit, but it seemed to work. Mycroft's penis twitched slightly in interest.

_Nicely done, Sherlock._

Sherlock grasped his brother's cock and shoved the entire thing into his mouth. He was fairly sure he could get his balls in there too, if he did it before Mycroft got too hard. He was just about to try when Mycroft's thoughts cut in.

_Silence, or there will be hell to pay._

Right. He brought his hands up to work the shaft and tugged on it gently in an effort to arouse his brother. He let his hot breath play along it. He kept at it for a couple of minutes as he lulled Mycroft into a false sense of security. He waited until the Foreign Minister was droning on about something, and then bit Mycroft's thigh. Through his trousers. Hard.

_Sherlock!_

_Yes, brother-mine?_

_What the hell do you think you're playing at?_

_You said you wanted a challenge. If I'd wanted to make it really challenging for you, I would have done it while you were the one speaking._

There was silence from Mycroft for a few moments, and the Minister droned on.

_I'm not sure whether to congratulate you for taking my challenge to heart, or to lubricate that toy with mentholated cream next time, Sherlock. Knowing you, they'd both amount to the same thing._

_Touch_ _é. It sounds like your boring friend might be finished with his thought. Your turn._ Sherlock turned his own attention back to Mycroft's cock, which was getting more interested despite the state of international finance; but not interested _enough._ Mycroft appreciated the finesse Sherlock brought to a blow-job, but he also liked to intersperse that with thrusts that were hard and fast. And, on two very different levels, this was neither hard enough nor fast enough.

Mycroft nudged Sherlock with his foot as he was talking to the Minister.

_You could just tell me, Mycroft; you don't have to be rude._

This time, Mycroft almost kicked him.

_He's almost done, you prat. Zip me back up._

Sherlock glanced up. Mycroft's hands were clasped neatly on the desk. It would be obvious if he reached under the desk to straighten himself out.

_It's not my fault he didn't stay long enough!_

_Oh, I disagree; I believe you failed, Sherlock. You're running out of time. Don't make me stall him._

Sherlock leaned back and felt the huge toy shift deep inside him. He wondered if he'd even be given a second chance, now that he'd failed at this one. He returned Mycroft's boxers to their original position as well as he could. In some respects, it was a blessing that his work had been inadequate; a firm erection would have made it much more difficult. He tucked Mycroft's shirt back into his trousers, grateful, for once, for his brother's perversely archaic tastes in clothing. Waistcoats covered a multitude of sins.

He'd barely finished re-buckling Mycroft's belt when his brother pushed the chair back from his desk and walked the Foreign Minister to the outer office. Sherlock slumped back against the desk in a heap. He'd failed. Mycroft returned, alone, and the door clicked shut; then he heard the bolt. His heart raced for a few beats until he realised Mycroft was just giving them privacy so he could change back into his clothes. Mycroft would be done with him for the afternoon.

"You may come out, Sherlock." His tone was even and betrayed nothing of his mood.

He crawled out on his hands and knees, his erection flagging from disappointment.

"Oh, cheer up, Sherlock. You made a decent effort. You just weren't _good enough,_ were you?"

Sherlock shot him a filthy look as he stood up, only to realise that his brother was smiling broadly.

"I'd never admit it if it wasn't your birthday, but a second orgasm so soon? In that period of time? You were up against losing odds, dear brother. It would have been a small miracle if you'd done it. Although the bite through my trousers did give me quite a start; I was glad you waited until I wasn't speaking.

"He sounded incredibly self-absorbed, My. I'm not sure he'd have noticed if you'd screamed my name out."

"Mm. That's quite possible. It's a shame I can't test that theory."

They wandered into the toilet where Sherlock had stashed his clothes.

"I should be finished for the day, you may ride home with me." He was interrupted by the crisp sound of the intercom in his office.

"Sir?"

"Oh, blast."

He strode back to his desk and pushed the button. "Yes, Anthea?"

"I'm sorry, sir. I know you're busy, but the Home Secretary just phoned, and he's on his way over right now."

"Very well, thank you."

He went back into the toilet with renewed purpose. "It looks like you just got a second chance, little brother."


	3. Second Chance

**Summary for the Chapter:**

> Sherlock gets a second chance to redeem himself, and Anthea proves her worth as a Personal Assistant.

**Notes for the Chapter:**

>  **Warnings: DO NOT try this** with Tiger Balm or any other sort of muscle rub. There is a reason they have warnings on this stuff about not using it on mucous membranes. (I did try it once, it was a big mistake.) Again, DO NOT try this. Please.
> 
> If you want to experiment with this sort of pain/sensation play, research 'figging' - anal play with peeled ginger. Deklava's excellent story, [_'The Spice of Strife'_](http://archiveofourown.org/works/466804), mentions it.
> 
>  **Other warnings:** sibling incest
> 
> Thanks to Deklava for the beta.

Mycroft closed and locked the door. "This time, the stakes are higher. On your knees again; arse in the air."

Sherlock's groin tingled; _higher stakes._ That either meant punishment or the threat of it. Either way, his mouth started to water at the thought. He craned his neck so he could see Mycroft.

His brother opened a small cabinet on the wall and pulled out a tube of lubricant and a small jar of Tiger Balm. He mixed them together in his palm. "You see what I'm doing, Sherlock?"

He nodded. Of course he did. The anticipation of the burning pain it promised had him throbbing with desperate need.

"Do you think you can keep quiet enough to do this? The only gag you'll have is my cock in your mouth."

He nodded once more, too overcome with anticipation to speak.

"Good. Relax." Mycroft pulled the toy from his arse, smeared the doctored lubricant all over it, and shoved it back inside.

Sherlock sucked in deep, gasping breaths as his brother went to the sink to wash his hands. It didn't just burn, it radiated fire through every nerve ending in his arse. His eyes watered and he struggled to retain his composure.

"How does it feel Sherlock?"

He tried to respond, but all that came out was an anguished moan.

"Do you want to call safeword?"

He shook his head, vehemently. It was torture, but it was delicious torture. The trails of pre-ejaculate hanging from his cock were a testament to that.

Mycroft smiled. "I know you can do this. Just think of what I'll do to you after the Home Secretary leaves; that should pull you through. Now, get back under the desk, we don't have much time."

Sherlock stood, the new position pushing the torturous lubricant deeper into his arse. He bit his tongue to focus the pain elsewhere as he hurried nakedly to his position beneath Mycroft's desk.

Mycroft sat down to wait for his visitor.

Sherlock tried to distract himself by rubbing his hands along Mycroft's clothed groin. Strong, delicate hands batted him away. "Do that again, and you won't get a second chance," Mycroft hissed. "You don't get to start until after my meeting does. And don't get any ideas about relieving your own tension. Play with yourself if you want, but if you come, you'll be wearing that chastity device for a week. You'll be my own personal glory hole, and you won't get anywhere near an orgasm until I take it off."

Sherlock had considered stroking himself a little to focus his mind away from the exquisite burning torture in his arse, but that - the chastity device - wasn't worth it. It was a clear polycarbonate cage for his cock that secured behind his balls. It allowed him to urinate and bathe, but it wouldn't allow him to get an erection or have an orgasm. Mycroft was right - deprived of orgasm, he'd basically be nothing more than a tight, wet hole and a willing mouth. Even if Mycroft fucked him, there was no way he could get off on it. It was one of the few tortures he quite literally couldn't enjoy. While the idea of being just another one of Mycroft's sex toys appealed to him on an intellectual level, the reality of it was far different, and one he didn't care to experience again if he could avoid it.

He sat back on his heels and used the position to move the plug in his arse. The pain brought his mind back to a sharp focus and chased away the distracting image of being chained to the foot of Mycroft's bed as a fuck-toy.

The intercom sprang to life. "Sir, the Home Secretary is here to see you."

Mycroft pushed back the chair, and with a departing whisper of, "Good luck, Sherlock," he went to greet his visitor.

The logistics of this session were very similar to the last, except that each small movement on his part resulted in a tingling pain that felt like someone was fucking him with a cactus. It seemed that Mycroft's knowledge of his condition was at least having some effect though; where before he'd been completely soft, this time he was semi-hard by the time Sherlock got his pants down.

Sherlock was fairly certain that at least some of Mycroft's discussion was classified, but he had more interesting things on his mind, and in his mouth. The meeting was definitely longer than the previous one; Sherlock had gotten Mycroft hard and had started to hold out hope of actually making him come. The pain in his arse dulled to a constant thrum as his nerves became accustomed to it and his brain became more occupied with pleasuring his brother. There was no time for distractions - every second counted if he was to make Mycroft come. He wished he had access to his brother's arse - shoving a finger or two up there would certainly speed things along - but that was a logistical impossibility. One spit-slick hand stroked Mycroft's shaft at a furious pace; the other cradled and massaged his balls. His mouth was filled with the fat head of his brother's cock, and he used every technique he could think of to bring his brother closer.

At one point, he glanced up to see Mycroft's hands clenched in a death-grip on the arms of his chair. Sherlock smiled to himself. He might be able to pull this off.

He tongued his brother's slit, thrilled to taste the salty fluid that gathered there; he was getting close. He busied himself with the sensitive area just beneath the head of his cock; if anything was going to get him off, this would.

Mycroft's restraint was phenomenal though, and he seemed to be winning the battle of wills. Then, as if things weren't bad enough, Mycroft rubbed the leather sole of his shoe against Sherlock's erection. Slowly and deliberately.

Sherlock was glad his mouth was full, or he probably would have made some sort of noise. He tried to move away, but Mycroft seemed to follow him; it was a small space beneath the desk, after all. Sherlock dropped one hand to his balls and tugged on them to relieve the pleasure that threatened to overwhelm him.

Then Mycroft gave him a soft kick, and Sherlock almost snarled in frustration. He'd lost again. He pulled off his brother's cock and returned his attentions to his shirt and trousers. Mycroft's erection made that a lot more difficult this time, and once again, he was thankful for the waistcoat. He caught his brother not so subtly repositioning himself under the desk so his erection would be less obvious to his guest.

Mycroft gave Sherlock's erection one last affectionate rub with the toe of his shoe, and Sherlock smiled. No grudges then. It _was_ his birthday after all. He eagerly awaited his punishment and let himself focus on the delicious burning in his arse as Mycroft concluded his meeting with the Home Secretary.

"So, Sherlock," Mycroft said, as he once again returned to his office and locked the door, "you failed. Again. What do you have to say for yourself?"

"I got a lot closer."

"Indeed you did, little brother. I daresay you got pretty close yourself."

"Not too close, though."

"No, that's almost a shame, really. I do love controlling when you're allowed to bring yourself off. A punishment for another time, I suppose. Still, you failed, and that requires some sort of punitive action, wouldn't you agree?"

Sherlock tried not to agree _too_ enthusiastically.

"I'm going to fuck you over my desk."

That sounded fine to him. He moved to the desk and happily bent over it, arse in the air.

"Oh, I'm terribly sorry, Sherlock," Mycroft said in a voice that made it very clear he wasn't in the least, "but that cream is going to end up all over my cock if I fuck you like this. We need a condom."

"Fine."

"You seem to have forgotten, Sherlock; we don't use them, and I don't have any. You'll need to get one from Anthea; I'm sure she has a few in her handbag."

"Mycroft," Sherlock whined, "she's _your_ PA. Besides, you're the one who's dressed. Why should I have to get dressed and ask her?"

"Oh, of course. How rude of me." Mycroft went into the toilet and returned with Sherlock's underpants. "Here you are. Unless you'd prefer to ask her in your proverbial 'birthday suit'?" He smirked at his own joke.

"You have got to be joking," he sneered, but then he snatched his pants from his brother in a huff, before Mycroft could change his mind about letting him wear them. "Aren't you worried she'll tell someone about our 'relationship'?"

"Don't be absurd, Sherlock. She already knows exactly what goes on in here. Why do you think I pay her so well?"

Sherlock shook his head in disbelief as he pulled on his knit boxer briefs. They were tight, and with his raging erection they left absolutely nothing to the imagination. He ran his hand over his arse, and felt the base of the butt plug bulging beneath the material. _Oh dear God. This is humiliating._

The thought hadn't been meant for Mycroft, but apparently he'd heard it. "And you love every debasing second of it, little brother. Be sure to thank her properly; I want you to bend over and kiss those lovely expensive shoes of hers. Make sure she gets a good look at your arse. I'm sure she'll be amused to see that you're wearing a plug."

Humiliation and arousal were competing within him, staining his chest and face pale pink, and making his cock harder. He looked down and noticed with dismay that there was already a wet spot on his pants.

"Time's wasting Sherlock. If you're not interested in getting off, perhaps I should use the chastity device on you. It certainly doesn't prevent _me_ from getting satisfaction."

Sherlock barely heard the last part of the sentence as he rushed into the outer office.

If Anthea was surprised to see him, hard and barely dressed, she didn't show it. "Hello, Sherlock," she smiled. "How can I help you?"

"I need a condom," he said, trying desperately to be nonchalant.

"Of course. Could you pass me my handbag? It's over there, in the corner."

Sherlock could feel her eyes surveying him as he retrieved it from the coat stand.

"Are you having a nice birthday?" she asked, innocently, staring at the wet spot on his pants.

"Very nice. Thank you," Sherlock replied, trying hard to keep his voice level. He handed her the red patent leather designer handbag. "Are you sure you have enough of a view?" he asked, sarcastically. She _was_ still looking at his crotch. "I could always take these off if I'm leaving too much to your imagination," he added. A flash of movement caught his eye. Mycroft was standing in the doorway, observing him with a stern look on his face.

"Indeed you shall, little brother; there's no call for sarcasm. Take them off, now."

Sherlock swallowed. This wasn't his area _at all._ He slowly pulled down his pants; the front of them caught on his cock as he removed them and it sprung free.

Anthea looked mildly impressed.

"May I?" she asked, looking at her boss.

"Of course," Mycroft smiled.

She reached out and swiped her fingers over the dripping wet head of Sherlock's penis. She put them in her mouth for a taste. "Mm. Very nice."

"Now apologise to her for your attitude, Sherlock, and tell her why you need the condom."

"I'm sorry, Anthea. I shouldn't have been rude. I need the condom…" he couldn't actually finish the sentence. His body seemed incapable of it. His breath, his brain, his lungs - they were all conspiring against him to leave him standing there like a mute idiot. His heart pounded like a jackhammer from the combination of excitement and mortification. Besides, the reason was just too bizarre to admit to anyone else.

"Sherlock…" Mycroft warned.

"I need the condom…" he steeled himself and took a deep breath. The words came out in a rush in a surprisingly measured tone, "… so Mycroft can fuck me with ridiculously strong mentholated lube. He doesn't want to get any on himself." He took another breath, and added, "For obvious reasons," with a dirty look at his brother.

"Oh, that sounds rather delightfully painful." She dug through her handbag. "Right then," she said with a smile, "regular or extra-large?"

Sherlock sighed. "Extra-large." It was true, although he was tempted to torture Mycroft by asking for the smaller size. His brother seemed a little too eager to use the chastity device, and he was unwilling to push his luck.

"Of course. And how many?"

"Just the one, thank you," he said as he gave her a tight smile. He knew he must be bright red with embarrassment, but his prick was throbbing so hard it ached.

"Now thank her, Sherlock."

Sherlock dropped to his knees and bent over to kiss her feet.

"Ooh," she said with delighted surprise as she saw the butt plug. "He likes to keep you ready, does he?"

Sherlock muttered his agreement as he kissed her hideously expensive shoes.

"I must say though, I never realised your arse was quite that nice. I'm glad someone gets to enjoy it," she added, cheerfully.

Mycroft smirked. "Thank you so much, Anthea. I doubt Sherlock will be able to keep his vocal enthusiasm to himself, so you may take the rest of the afternoon off."

"Thank you, sir."

Mycroft turned and retreated back into his office.

Anthea smiled at him sweetly, and said, "Happy birthday, Sherlock." Then she silently mouthed the word 'slut' and gave him a huge smile.

Sherlock briefly closed his eyes and took a deep breath at the sheer humiliation of it all. Then he picked up his ruined pants and the condom and returned to his brother's office.


	4. A Personal Appointment

**Summary for the Chapter:**

> Sherlock and Mycroft finally get some time alone.

**Notes for the Chapter:**

>  **Warnings** : **DO NOT try this** with Tiger Balm or any other sort of muscle rub. There is a reason they have warnings on this stuff about not using it on mucous membranes. (I did try it once, it was a big mistake.) Again, DO NOT try this. Please.
> 
> If you want to experiment with this sort of pain/sensation play, research 'figging' - anal play with peeled ginger. Deklava's excellent story, 'The Spice of Strife', mentions it.
> 
>  **Other warnings** : sibling incest
> 
> There is NSFW art by the amazingly talented [sexlock](http://sexlock.tumblr.com) at the end of this chapter! Many thanks to the lovely [Deklava](http://archiveofourown.org/users/deklava/pseuds/deklava) for commissioning this!

"Best personal assistant I've ever had," Mycroft smirked.

"She's as much of a perv as you are."

"She doesn't apologise for the things she enjoys, if that's what you mean. Nor, if I recall correctly, do you. Although," he added with a grin, "sometimes you might be better off if you did."

Sherlock smiled and muttered, "I believe I've been doing _that_ all afternoon."

Mycroft pushed a button on his desk that locked the door to his office. "You're not finished yet, brother-mine. And I must say," he smirked, as he pushed Sherlock against the wall and rubbed his clothed erection against Sherlock's naked thigh, "I've been particularly looking forward to this. Although," he mused, "what I have planned for you… I do wonder if it's too much. Perhaps I should just take you out for a lovely meal and we could spend the evening having non-threatening romantic sex with no power dynamic whatsoever."

Sherlock gave him a short laugh. "Tell me, where's the fun in that?" He pulled his brother close and whispered, "I can take whatever you can dish out, Mycroft. You know I get off on the pain. Make me come so hard I scream."

"Mm. Well, if you're so confident, let's get on with it, shall we?" He pressed a slow, hot kiss against Sherlock's mouth. "You know how I love the sound-proofing in here."

Sherlock wondered, just for a second, what Mycroft had in mind. The plug had been intense, and when they were in the mood for it, sex with Mycroft could be particularly rough. Still…

"Alright, Sherlock. You failed to get me off in not one, but two meetings. I'd like to use the lubricant on your cock as well as your arse. Are you willing?"

Sherlock drew in a quick breath of excitement and his groin started to tingle in anticipation. _So that's what he has in mind._ "Yes. God, yes."

They were in the toilet. Mycroft already had the cream and the lubricant out, and he removed a third, unmarked bottle from the cabinet, along with a pair of nitrile gloves.

"What's that?"

"An antidote, of sorts. Vegetable oil. When we're finished, or if things get to be too much, we'll use it to remove the doctored lubricant. It makes it easy to remove the concoction from your skin."

"It acts as a solvent for the other oils."

"Yes." Mycroft cupped his chin and gave him a brief kiss. "You haven't been screaming in agony all afternoon, so I'll assume the mixture from earlier was stimulating but not overwhelming?"

Sherlock nodded.

"Good. I don't want you to end up at A&E. I plan on fucking you, hard - do you want me to make it any weaker to account for that?"

"No."

"Very well," he smiled proudly. He mixed the items in the same ratio as before.

"The oil in that will compromise the integrity of the condom, you know."

"Yes, but it's not like we're using it for birth control. Besides, I'm not completely averse to a little pain, myself."

Sherlock's eyes widened with surprise.

"You don't know everything about me, little brother. Not yet." He gave Sherlock a smile so enigmatic it would have put the Mona Lisa to shame. "Now," he said, moving quickly away from the subject, "you saw the ratio I used. Mix up a second batch for your cock. You may make it as strong or as weak as you wish." Mycroft casually undressed as he talked, placing his clothes in a neat pile on a small table near the sink.

Sherlock grabbed the small jar and scooped out a large amount of the liniment and mixed it with a small amount of the lubricant.

Mycroft raised his eyebrows in surprise, but said nothing. It was more than twice the potency he'd used for Sherlock's arse.

Sherlock gave his brother a smile of pure challenge.

"It's your pain threshold, Sherlock, not mine. Now, if you're ready, I believe I'd like to get started. Safeword if you need it - I'm not going to gag you. I'm sure the soundproofing was originally a security measure, but I'd much rather use it for this, wouldn't you?"

Sherlock responded with a wry smile.

"Right, on your knees." He handed Sherlock the condom. "Use your mouth."

A flicker of panic crossed Sherlock's features. He put it in his mouth and fumbled with it as he tried to stretch it over the head of Mycroft's cock using only his tongue.

Mycroft pulled him off with a sharp tug on his hair and retrieved the spit-covered latex from Sherlock's mouth. "You'd make a useless whore, little brother. Good thing you belong only to me." He rolled the condom over his straining cock and pushed it deep inside Sherlock's mouth, deep enough to cut off his air supply. He waited.

Sherlock knew this game. Loved this game. Even the taste of the latex, odd as it was, couldn't diminish it. All his focus went into willing his body not to betray him. If he struggled for air - if his body betrayed him, because he would never do it willingly - he lost. If he retained his focus until he passed out, he won. He rarely won; the body's need to survive was too strong. Mycroft never held him in place; that was part of the game.

He eventually pulled away, despite himself and sucked in deep, gasping breaths. "Sorry Mycroft," he choked.

"One of your better efforts, though. Now, turn around - I want to get that plug out of you so I can force this inside you instead."

Sherlock, already on his knees, turned and dropped his shoulders to the floor, presenting his shapely arse nicely.

Mycroft turned the plug slowly. "Does it still burn, Sherlock?"

"A little. Not as much as it did."

"Oh, I'm going to change that." He pulled the plug out in one sharp move, and Sherlock hissed at the sudden emptiness.

Mycroft stood and put the plug by the sink, then put on the gloves. "Don't worry, I'll be stuffing you full soon enough." Swiping his hands through the weaker lubricant, he slicked up his cock thoroughly. Then, he scooped up the more potent lubricant into his gloved hands.

"You've always wanted me to fuck you in my office, haven't you? Letting you come in there wasn't enough for you."

He shook his head. "Please, Mycroft."

"Always wanting more. Go into the office and bend over my desk like the little slut you are. Make sure I can reach that lovely cock of yours."

Sherlock arranged himself so he was braced against the desk. He felt Mycroft behind him, rubbing both gloved hands all over his engorged prick. He gasped as the potent lubricant touched his skin. It burned like fire. Mycroft rubbed it slowly across his entire cock, and then dabbed it just inside his slit. Sherlock wanted to scream, but it felt like the breath had been sucked out of his lungs.

Mycroft heard the pain that seared Sherlock's thoughts. _If you need to safeword, just think it. I'll hear you._ And then, _I've got you, little brother. You can do this._

Sherlock stood gasping with tears leaking from his eyes for a while, before he uttered, "More."

Mycroft covered his balls in the evil concoction.

It added to the pain - the burning glow encompassing his genitals - but it didn't eclipse the burning in his cock. He needed another point of focus. _Do it, Mycroft. Fuck me._

Mycroft binned the gloves to prevent the super-strength lubricant from accidentally getting on his cock and inside his brother. He lined up against his wet, loose entrance. The plug had done its job.

"Is this what you need, Sherlock?" he asked, as he plunged in to the hilt, the fiery lubricant easing his way and generating a throaty scream from his brother.

Sherlock was assailed by twin points of pain, equally fierce and bright in his mind's eye. The lube on his cock was stronger, but Mycroft was fucking his arse, hard.

His entire world narrowed to those two points, balanced on a fulcrum somewhere at his core. He heard a low keening sound in the distance, but he was unaware that it was his own voice. His eyes were shut now, and he was caught up in a world consisting entirely of sensation. His brain was interpreting the pain as visual phenomena as well as physical stimuli.

The two points increased in brilliance, pulsating and growing with both his heartbeat and his brother's thrusts. They grew until they merged into one blinding light that threatened to overwhelm him, and he struggled to keep it contained.

Mycroft's thoughts reached out to him, cutting through the hyper-stimulated screaming of his nerves. _Stop fighting it, little brother. Give yourself over to it. Come for me._

The words were a revelation. He screamed with relief as the light exploded into a million shards and he came all over the side of his brother's desk.

Mycroft was gone then, which confused him, but it made sense a moment later when oil-soaked wet-wipes soothed his burning cock and arse. He could feel that Mycroft was wearing gloves again, but this time they must have been covered in oil, not lube, as gentle fingers neutralised the burn inside him.

"Are you alright, Sherlock?"

He nodded, a bare flick of the head.

"Does it still burn anywhere?"

 _No._ Thinking was easier than moving or speaking.

Mycroft pulled him upright so their bodies were together. Sherlock melted into his brother's embrace, unable to process anything more than the comfort of his brother's skin. Mycroft led him to the sofa and wrapped them both in something soft, and Sherlock let the warm darkness close in around him.

When he came to, Mycroft was still there, holding him.

"Sherlock," he said, his voice full of warmth and affection. He smoothed his brother's dark hair from his cheek. "How are you feeling?"

Sherlock ran through a mental inventory. Everything was still there. "Cleansed," he said with a quiet smile.

_I saw bits of it through your mind. It was breath-taking, Sherlock._

_Yes, it was. I'll tell you about it later, I promise. I just need this…_ He curled back against his brother, seeking more contact with his skin. _Just for a while more._

_Take all the time you want, my love._

* * *

**_Birthday Present_ by [sexlock](http://sexlock.tumblr.com)**  



End file.
